Refinement and Implementation of the Automated Oligosaccharide Synthesizer Project Summary Carbohydrates form the basis of all living organisms and, as a consequence, are ubiquitous both in nature as biologically active compounds and in medicine as therapeutics. Although there has been continued interest in the synthesis of carbohydrates, and the inherent complexity of these molecules consistently captures the attention of many scientists, methods for the isolation, chemical or enzymatic synthesis, analysis, and application of carbohydrates remain cumbersome. Ever-increasing time constraints and cost limitations on research and development in glycoscience and glycotechnology call for the development of rapid, efficient and operationally simple procedures. While this represents an immense task, this proposal will focus on the introduction of an affordable and accessible automation platform that will enable both specialists and non- specialists to perform the synthesis of glycans. Current automated methods for the synthesis of oligosaccharides are highly sophisticated, operationally complex, and require significant user know-how. By contrast, high performance liquid chromatography (HPLC) equipment-based automation introduced by Demchenko and Stine represents a highly accessible method of synthesis. This is because many glycoscientists have operational knowledge of, and easy access to, HPLC equipment. The automated synthesis offers not only operational simplicity by delivering all reagents using standard autosamplers, but also convenient real-time reaction monitoring of every step using detectors and standard computer software and interface. We achieved faster reaction times using less reactant, reagent, and solvent than manual solid-phase synthesis. Building upon promising preliminary results, this proposal aims to generate a user-friendly, universal platform for automated and transformative synthesis of glycans. While the proposed automation approach has the potential to revolutionize glycan synthesis, practically every aspect of solid phase synthesis needs to be refined. This proposal is organized into four specific aims. The first three aims are dedicated to the refinement of inherent limitations of solid phase synthesis: 1) new affordable resins and the universal linker for solid phase synthesis; 2) new concepts for catalytic and stereocontrolled glycosylation; and 3) new methods for streamlined access to building blocks. The fourth aim is dedicated to the implementation of autosamplers as a mode for automation of the oligosaccharide synthesis. Upon completion of the proposed studies, we expect to have acquired a reliable and simple platform for automated oligosaccharide synthesis. Many classes of compounds can be obtained using solid supports; therefore, the proposed study is expected to be of valuable methodological and practical use to many scientists. Investigators with access to standard HPLC equipment should be able to perform automated synthesis of glycan libraries using our reagent kits or easily interface with their existing methods and equipment. Synthesis of carbohydrates and other classes of biomolecules using this user-friendly, automated platform will accelerate discovery in many scientific disciplines and can significantly impact technology, society, the economy, and public health.